Starship Troopers by Robert A. Heinlein

Starship Troopers is perhaps one of the best known of Heinlein's novels among the mainstream literary crowd. He took a lot of heat for it, and was accused of being a fascist for some of the things he wrote there. Indeed, he created a society which, on the surface, seemed to be ruled by the military, but in fact, citizenship was granted by performing two years of "federal service", which might have been military, but could include many other types of service, as well. The premise is that the franchise should not be granted to anyone who was not willing to demonstrate by their actions that they were dedicated to the welfare of the commonwealth.

This particular story thread follows Johnny Rico, a young man who comes from an aristocratic background, as he blindly volunteers to serve after graduating from high school, through his training and indoctrination in the Space Force, and his subsequent career fighting the Bugs, an arachnid race with a group mind, who are bent on eradicating humans from the galaxy.

Heinlein was a very clear-eyed realist about human nature. In a History and Moral Philosophy class that young Johnny, like all of his peers, is required to take, the instructor, Mr. Dubois, demolishes a popular argument by one of the students:

"My mother says that violence never settles anything."
"So?" Mr. Dubois looked at her bleakly. "I'm sure the city fathers of Carthage would be glad to know that."
"...Violence, naked force, has settled more issues in history than has any other factor, and the contrary opinion is wishful thinking at its worst. Breeds that forget this basic truth have always paid for it with their lives and their freedoms."

Another good quote:

(Sargeant) Zim said almost gently, "You've got it all wrong, son. There's no such thing as a dangerous weapon."
"Huh? Sir?"
"There are no dangerous weapons; there are only dangerous men."

He seems almost prescient with this bit:

"There is an old song which asserts that 'the best things in life are free.' Not true! Utterly false! This was the tragic fallacy which brought on the decadence and collapse of the democracies of the twentieth century; those noble experiments failed because the people had been led to beliee that they could simply vote for whatever they wanted...and get it, without toil, without sweat, without tears."

And talking about juvenile delinquents:

"Were they scolded? Yes, often scathingly. Were their noses rubbed in it? Rarely. News organs and officials usually kept their names secret - in many places the law so required for criminals under eighteen. Were they spanked? Indeed not! Many had never been spanked even as children; there was a widespread belief that spanking, or any punishment involving pain, did a child permanent psychic damage...pain is the basic mechanism built into us by millions of years of evolution which safeguards us by warning when something threatens our survival. Why should society refuse to use such a highly perfected survival mechanism?"

This novel has, nakedly scattered through its pages, probably the most commentary about politics and society of any of Heinlein's works. And yet, it's an engaging read, with an interesting plot, and realistic characters througout. The military organization and tactics described within it bears only a passing resemblance to any force on Earth today, but the underlying philosophy of conflict and honorable behavior shines through clearly.

Quintessential Heinlein.